langchain/docs/ecosystem/unstructured.md

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# Unstructured
This page covers how to use the [`unstructured`](https://github.com/Unstructured-IO/unstructured)
ecosystem within LangChain. The `unstructured` package from
[Unstructured.IO](https://www.unstructured.io/) extracts clean text from raw source documents like
PDFs and Word documents.
This page is broken into two parts: installation and setup, and then references to specific
`unstructured` wrappers.
## Installation and Setup
- Install the Python SDK with `pip install unstructured[local-inference]`
- Install the following system dependencies if they are not already available on your system.
Depending on what document types you're parsing, you may not need all of these.
- `libmagic-dev`
- `poppler-utils`
- `tesseract-ocr`
- `libreoffice`
- Run the following to install NLTK dependencies. `unstructured` will handle this automatically
soon.
- `python -c "import nltk; nltk.download('punkt')"`
- `python -c "import nltk; nltk.download('averaged_perceptron_tagger')"`
- If you are parsing PDFs, run the following to install the `detectron2` model, which
`unstructured` uses for layout detection:
- `pip install "detectron2@git+https://github.com/facebookresearch/detectron2.git@v0.6#egg=detectron2"`
## Wrappers
### Data Loaders
The primary `unstructured` wrappers within `langchain` are data loaders. The following
shows how to use the most basic unstructured data loader. There are other file-specific
data loaders available in the `langchain.document_loaders` module.
```python
from langchain.document_loaders import UnstructuredFileLoader
loader = UnstructuredFileLoader("state_of_the_union.txt")
loader.load()
```
If you instantiate the loader with `UnstructuredFileLoader(mode="elements")`, the loader
will track additional metadata like the page number and text type (i.e. title, narrative text)
when that information is available.